Growing Madder in Alberta

A number of years ago, when we lived in Lethbridge, AB, I ordered some madder seeds from you and had great success with them. Lately, thanks to the Internet, there has been some discussion amongst natural dyers about the cultivation of madder. Some of the dyers are growing it in containers (ie: a large garbage can, cut in half with holes in the bottom) and I started wondering about doing the same here.
We live in Red Deer, AB, Canada and I was wondering if it would be possible to grow madder in half of a whiskey barrel. Of course, my chief concern is over wintering since I will need to leave them grow for at least 3 years. Any suggestions?

Unfortunately your zone 3 climate is far too severe to allow madder to overwinter successfully outdoors. A barrel would make the roots even more vulnerable to freezing. Madder is hardy to zone 6 while the Indian madder is a tropical plant. The former would have to have its barrel moved into a root cellar, very cool bedroom or slightly heated garage to make it through the winter. The Indian madder would have to be moved into a frost free area.